Thomas Sanger

RESEARCH INTERESTS

I am fascinated by the striking diversity in size, shape, and color of modern vertebrates. My lab’s research strives to create a deeper understanding of the evolutionary mechanisms underlying the diversity of anatomical form. Our work in inherently integrative, pulling tools from fields as diverse as ecology, phylogenetics, developmental biology, and genetics. The consistent, uniting theme across all of our studies is a passion for understanding organismal diversity. We currently have three active research foci.

1.The effects of thermal stress on reptilian embryos There is no debate. Climate change is warming our world. In recent years’ ecologists and conservation biologists have raised concerns about stresses these increasing temperatures will place on of terrestrial ectotherms, animals whose thermal niche is closely tied to their environment. Many of these studies are focused on adult ecology and rarely have the direct effects on embryonic development been explored. Using Anolis lizards a model system, we are investigating the ways that thermal stress will disrupt normal embryonic development, what organ systems are most sensitive to thermal stress, and what molecular pathways are most likely to be disturbed by thermal stress.

Vertebrates are covered with an array of skin-derived appendages such as hair, feathers, nails, glands, or scales. Strikingly, most of these structures have similar embryological origins despite the diversity observed in adult form. What remains unclear are the specific evolutionary steps that underlie the diversification of these dermal appendages.

2. The evolution and development bases of reptilian scale diversity. Reptilian scales are presumably the structure that other skin appendages are evolutionarily derived from, but little is known about the development of scales in squamates, lizards or snakes. We would like to know more about the development of different scale types. More specifically, we would like to know how specialized adhesive scales on the toes of Anolis lizards were derived from the more typical plantar scales observed among other iguanid species. This project involves a variety of newly developed techniques such as ex ovo embryonic culturing and live imaging.

3. The evolution and development bases of mammalian plantar Take a look at the paws of a dog or cat and you will see enlarged, heavily keratinized pads that make contact with the ground while the animal is walking. These are common throughout many mammals. Even humans have these pads during the early embryonic formation of the digits during the 10th through 14th week of development. Despite several human conditions where skin fails to properly form on the pad forming regions, little is known about proper pad development. We are developing the use of transgenic mice as model systems for normal pad development. These results will be used to inform human conditions and to create a better understand the diversity of pad size, shape, and number among mammals.).